This invention is generally related to a geometric configuration of a combustor chamber. More particularly, this invention is related to an annular combustor chamber including a convergent segment and a divergent segment.
Conventional gas turbine engines include a compressor, combustor and a turbine. The combustor may be of several configurations including an annular combustion chamber that is symmetrical about an axis of the engine. The annular combustor includes a segment where fuel is mixed with high-pressure air and ignited. The combustion chamber is shaped to encourage complete burning of the fuel air mixture and to provide a desired flow of combustion gases through to the turbine.
Emissions that are generated by the gas turbine engine are a concern and consideration in the design and operation of a combustor. Undesirable emission performances are caused by the stoichiometry inefficient mixing of fuel and air both spatially and with time through the combustor volume. For this reason, combustors are designed to encourage highly efficient mixing of fuel and air and control the stoichiometry of the fuel-air mixture. Further, it is also desirable to exhaust combustion gases from the combustor in a well-mixed homogeneous manner.
Disadvantageously, mixing of air and fuel within a combustion chamber takes time, time that combusts the fuel-air mixture to high temperatures thereby causing production of undesirable emissions such as nitrous oxide, carbon monoxide, carbon dioxide, and other hydrocarbons as a result of incomplete combustion or locally-supported stoichiometry.
Accordingly, it is desirable to develop a combustor assembly that provides desired mixing of fuel and air and that reduces residence time within the combustor to reduce the production and emission of undesirable combustion by-products.